Amazon After you cut your glass, usually you would want to have smoother edges, or you have a bump somewhere that you want to get rid of. There is a wide array of tools you can use to smooth your glass. Most of them work by rotating a specialized surface with water on it, and you rub your piece against it to make it smooth. There is this machine that runs a thick belt and you rub your piece against it. In general they are easy to use; you just need to put on goggles to prevent little pieces from getting into your eyes!

Decorating your piece is the meat of the whole process. Usually you decorate glass with other pieces of glass, which can be of different color, shape, and so on. There is a wide range of materials such as glass powder and thin glass sticks.
Here's one glass piece I made with many small pieces of colorful glasses sitting on top of a bigger piece of clear glass. I even used red thin glass sticks to write a Chinese character: